Equivalent expression of endogenous murine leukemia virus-related genes in C3H/10T1/2 cells and chemically transformed derivative cells.

The possibility that chemical carcinogens may induce enhanced expression of endogenous C-type RNA tumor virus genes in the absence of intact virus particle production has been partially tested in a model system. Thie was accomplished by measuring the abundance and diversity of murine leukemia virus-related RNA sequences associated with the polyribosome fraction of nontransformed C3H/10T1/2 clone 8 cells and a 3-methylcholanthrene-transformed derivative clone. Although both clones are virus nonproducers, they were found to contain significant amounts of polyadenylate-containing murine leukemia virus-related RNA sequences; however, both the types and quantities of such sequences appear indistinguishable in both clones. These results suggest that expression of the corresponding gene sequences into RNA is not related to the maintenance of the transformed state in these chemically transformed cells.